1. Field of the Invention
The invention relates generally to display systems and, more specifically, to a system and method for dynamically configuring a serial data link in a display device.
2. Description of the Related Art
Computer systems typically include a display device, such as a liquid crystal display (LCD), coupled to a video data link that transmits frames of video data from a graphics processing unit (GPU) to the display device. During normal operation, the GPU generates sequential video frames, each comprising a two-dimensional array of individual pixels. The video frames are typically generated by the GPU and stored within an associated frame buffer. Each video frame is then scanned out by the GPU as pixel data. The pixel data is transmitted via the video data link to the display device for display of a corresponding video frame.
The video data link comprises one or more lanes, each configured to transmit a bit of pixel data during a bit time interval. Each lane comprises a physical signal path, such as an electrical differential signal path. Manufacturing variation in the GPU, physical signal paths, and display device can impact the signal integrity of pixel data being transmitted via the video data link. Instantaneous temperature and voltage variation in the GPU and display device electronics can also impact the signal integrity of data on the video data link. One bit time conventionally represents such a small time interval that normal manufacturing variation in different elements associated with the video data link can significantly degrade signal integrity of the pixel data. Signal degradation includes, for example, lane to lane skew and selective frequency attenuation, which can degrade or close a signal eye pattern. To mitigate such signal degradation, interface circuits associated with the video data link execute a link training procedure to compensate for skew, frequency attenuation, and so forth.
Each time the video data link is activated, the link training procedure is performed on the video data link prior to transmitting pixel data to ensure proper signal integrity for the pixel data. The training procedure may take more than an entire frame time in certain scenarios, leading to an interruption such as a flicker, or temporary blanking of the display device. In certain scenarios, a computer system may need to transition between display modes that require the operation of the video data link to be modified, leading to a new link training procedure that can potentially disrupting proper display of frames on the display device. Such disruption can cause the display device to flicker or blank one or more frames, thereby degrading image quality.
As the foregoing illustrates, what is needed in the art is an improved technique for managing pixel data transmission between a GPU and a display device.